Induction heating unit



Jan. 5, 1954 N. .1. cuTLu-F ET AL INDUCTION HEATING UNIT Filed April l2, 1952 QLILIU uulnlLlLlLnJH JNI/ENTORS Qlofunan Jguffiff vmnef /wgcub figg Patented Jan. 5, 1954 2,665,363 INDUCTION minxrfnvaL UNrr Norman J. ,onuiff and Emmett v. Brogan, Louisville, Ky., assignors toInternational Harvester Company, a. Vcorporation of New Jersey- Application April 12, 1952, serial No.r 281,992.A

This invention relates ,tocan induction heating unit and more particularly to an improvement in an induction coil.. More Speeieellv the lllvention relates, toan--improvedinduction heating coil particularly; adaptable for heating bi1- lets andthe likeemployed in forging operations.

An induction heating furnace :of thevctype to which ,thepresentdmprovement applies is disclosed inl the "patent to Strickland. Number, 2,408,359 patented September 24, 1946. The type of heating LuiitA shown in this patent is utilized inthe heatingof billets or the like and the heating unit comprises essentially a tubularv refractory element around which the Vcoil-turns of an induction coil are-disposed. The refractory tube serves to support the billets during their travel through the furnace and also serves to heat insulate thevcoils ovfthe induction unit. In this patent the refractory tubular member consists'of a pluralityof individual segments or pieces which are suitably cemented together to form aV cohesive structure. In induction coils of thistype it is desirable Ato provide a plurality of tracks'within, theerefractory, these tracks serving to guide and tosupport the metal billets as they travel through Vthe furnace. Invthe above mentioned applicatif'in guide rails of this type are-employed, the guide rails being tubular in construction so thatl proper coolingof the rails may be eiected `during their operation. The rails or `tracks of ther Strickland patent are embeddedwithin the refractory tube andthis em-V bedding takes place during the assembling or construction of the furnace, the tubes being held in position by the mortar which is disposed between the individuel errements .of the refraciOy- Portions. efe, hardened ,materialen ,eenlleeledte the tubular embedded members and these hardened portions serve to act assguide elements or tracks Vlot-tbe billets .durineitheir travel tbroueh .tbe-ind11ction furnce.-

In practice with the use of furnaces of ,the type above indicated ithasbeen found that .the tracks will frequently have' to be replaced `and i'.hatethis` iSV quite a costly .procedurefsincethe coilV hasA tobe Vcompletelyibrokenwdoyvn. This breaking down of-the coil takesj place vduring .the removal ofthe tracksvcsince v'they are Aembedded' in be-v tweenthe. indlvdualzsegmellts yor sections ofthe tubular refractory@ A tubulaire-refractory which, iS made upof. individual breksorsegments also inpractice hasbeen found vto -be expensivefrom the standpoint of maintenance since individual portions ,or bricks wouldfbeeome l,loosev c luldlrieuee,l

@dessine of c the .;.t11.bi1 1ar refractory.. as ia ..unnl

sciaims. (ci. 21e-47) would take place. It can be appreciated that any breakdown of the refractory might occasion improper operation since scale forming onthe heated billets will verylikely travel through the broken portions of the refractory and become erigaged with portions of the induction coil Whereupon the coil will short-out and cause improper operationv It is a prime object of this invention therefore to provide an improvedconstruction in induction furnaces or induction coils the induction unit being inexpensive in construction and in rnaintenancey A- still furtherv object is to provide an improved induction coil .having a pair of longitudinally extending liquidcooledtracks, the tracks being readily removable from the induction coil for replacementapurposes Without damage or deterioration of the refractory tube which is constructed Within the induction coil.V

Anotherobject is tol provide an improved induction coil comprising a pair of longitudinally spaced supports `positionedto support an integral or one piece refractory ktube which is surrounded. or encircled .by means ofan induction coil, the refractoryhaving contained therein Va pair of longitudinally extending water cooled tracks the tracks being connected tothe coil for ready removal and replacement. v Y

Astill furtherV object is to provide an improved induction coil 'having a pairof longitudinally spaced supports the supports including center openings inlongitudinal alignment for supporing a one piece refractory tube, the refractory tube being arranged to support an induction coil which encircles said tube, the unit further including Ya, pair of water-cooled tubular tracks which rest upon :and project from the inner smooth surfaceof the yrefractory tube, the tubular tracks` beingvremovably connected to inlet and outlet conduits in a'manner wherein cooling `of the tracks is facilitated and quick removal o f the tracks may be accomplished.v

A still furtherobject is to provide an improved inductionheatingv unit comprising a pairl of the manifold also including tubular connections which are connected to the induction coil for supplying a liquid coolant to said coil.

These and further objects will become more readily apparent from a reading of the specification when examined in connection with the accompanying sheets of drawings.

In the drawings:

Figure 1 is a plan view of an induction heating unit embodying the features of the invention;

Figure 2 is a front View in elevation of an induction heating unit.

Figure 3 is a sectional view through an induction heating unit taken substantially along the line .3-3 of Figure 2; and' e Figure 4 is a sectional view through an induction coil taken along the line ii-t of Figure 1.

Referring now to the drawing, an induction heating unit is generally designated by the refer-" ence character it. The induction heating unit Hl comprises a pair of longitudinally spaced supports provided with center openings i2 which are in alignment. The spaced supports are preferably constructed of a non-conducting material such as wood, nbre, etc. A tube or hollow member i3 has its end portions suitably supported in the center openings i2 of the supports il. The tube I3 is constructed of a refractory material, the tube being in one piece or integral such as might be formed by a casting or extruding process. An induction coil i5 is carried by the refractory tube i3. The induction coil i5 comprises a plurality of interconnected coil-turns or coil sections i6 which as indicated in the present disclosure encircle the refractory tube i3 in a spiral fashion.

A collar il is connected to the outer face of each of the longitudinally spaced supports li. Each collar l? is constructed of silica carbide material which is very hard and heat resistant. The collars li include cut-outs iii and iianges l5. Suitable brackets 2t engage the iianges i9 for securing them against the outer surfaces of the spaced supports ii. In certain induction furnaces several of these induction units may be utilized and the collars il, which project from the outer faces of the supports i I may be placed in contiguous relation to form a bridge between the induction units to support the billets which may be passing through said units. A track generally designated 2i is provided within the refractory tube i3. The track 2l consists of a pair of longitudinally extending track sections or tubes 22 which are sup-ported in longitudinally extending recesses 23 provided in the inner cylindrical surface of the refractory tube i3 as best indicated in Figure 4. Each track section or longitudinally extending tube 22 is provided at its ends with laterally extending tubular end portions 2li. inlet conduits 25 extend through openings 26 in one of the supports ii, the inlet conduits being connected as indicated at 2l to a longitudinally extending manifold -or conduit 23 which is supported on the longitudinally spaced supports il. The inlet conduits 35 project outwardly from one of the supports ii and are bent in a suitable manner to register with the tubular end portions At one end of the tubes 22 threaded screw type inlet fittings 29 suitably connect the inlet conduits 25 and the tubular end portions 2t.

Outlet conduits 3i] are supported on the other spaced support H, the outlet conduits 3d extending through openings 3l in the support ii. The outlet conduits 3u are suitably bent to register with the tubular end portions 24 and are connected thereto by threaded outlet fittings 32. The outlet conduits 3) are also provided with suitable threaded fittings 33 at their other ends for connection to drain conduits (not shown).

The manifold 2s is provided with a suitable inlet 3s, the said manifold 28 being in communication with the tubular coil section It by means of a plurality of inlet conduits 35. Cooling liquid from the manifold 2t is thus delivered to the coil sections is through the conduits 35. Likewise cooling liquid to the track sections 22 is supplied from the manifold 28 through the inlet conduits 25. rlhe cooling liquid leaves the track sections 22 by means of the outlet conduits 3i) to a suitable drain. Likewise the outlets 35 provide for the discharge of the cooling liquid.

The operation of the induction coil i5 is conventional, since it is suitably connected to a source of high frequency power (not shown). The travel of cooling liquid from the manifold to the induction coil and to the longitudinally extending tracks also has been described. The structure is rigidly held in assembly by means of a plurality of longitudinally extending bars 31 which are oircurnferentially spaced about the induction coil i5. The bars Sl are constructed of a non-conducting material preferably such as wood, bre, etc. The ends of the bars 3l are suitably connected to the spaced supports il aS indicated in Figure 2 at 38.

The track sections 22 are made from a hard and high heat resistance steel, since the billets travel on the track sections 22 from one end of the induction unit to the other. In view of the Vextreme heat, it is found frequently necessary to replace the track sections and this can readily be accomplished by simply unscrewing the inlet and outlet iittings 2Q and 32 whereupon each track section 22 can readily be removed from the one piece refractory tube i3. Thus changeover and maintenance of the track sections 22 is a simple matter. The refractory tube which is manufactured in one piece can be used for a long period of time without any break-downs, this feature being of prime importance when considered in comparison with the maintenance problems presented by the built up or brick and segmental types of tubes discussed in the above mentioned patent. rThe novel arrangement of the manifold and its connecting parts with the coil and the tubular track are also believed to be of significance in the arrangement indicated since an inexpensive rigid and durable induction coil is provided.

It can now be seen that the objects of the invention have been fully achieved and it must be understoodv that changes and modifications may be made which do not depart from the spirit of the invention as disclosed nor from the scope thereof as defined in the appended claims.

What is claimed is:

l. An induction heating unit comprising a pair of longitudinaliy spaced, substantially parallel supports having center openings in longitudinal alignment, a one-piece refractory tube supported Within the openings, a hollow induction coil spirally wrapped around said tube and supported thereby, longitudinally extending members connecting said spaced supports, said members being circumferentially spaced about and engaging said induction coil in supporting relation, a track extending longitudinally within said tube, said track comprising a pair of laterally spaced tubular track sections supported on the interior sur-v fece ci the tube and. picketing therefrom., each ,iibiilar 'track Section presenting a continuous traclu surface projectingV Voutr'fvardly from the inner peripheral surface of the tube for supporting an object to be heated, tubular end portions on said track sections extending laterally with respect to the sections and the refractory tube, means for supplying and discharging cooling liquid to and fromsaid track sections including a manifold extending longitudinally substantially parallel. With said refractory tube, an inlet conduit for each track section, an outlet conduit for each track section, the inlet conduits being connected to said manifold for communication therewith and extending through said spaced supports, and rst removable conduit connections connecting said inlet conduits with the tubular end portions at one end of said track sections, and second removable conduit connections connected to the tubular end portions at the other end of said tracksections.

2K. An induction heating unit comprising a pair of longitudinally spaced substantially parallel supports having center openings in longitudinal alignment, a one-piece refractory tube supported by said parallel supports, a hollow induction coil encircling said tube, said induction coil including a plurality of spirally disposed coils, longitudinally extending supporting members circumferentially spaced about said tube for supporting said induction coil and tube, means connecting the end portions of said supporting members to said spaced supports, a track extending longitudinally within said tube, said track including a pair of laterally spaced tubular track s ections'supported on theinterior surface of the tube and projecting therefrom to present a continuous track section projecting outwardly from the inner peripheral surface of the tube for supporting an article to be heated, laterally extending tu'bular end portions on each end of each track section, means for removably connecting each track section to said refrac,toryV tube comprising inlet conduits supported by one of the parallel supports, inlet ttings connecting the inlet conduits to the tubular end portions at one end of the track sections, outletv conduits supported by the other parallel support, outlet fittings connecting the outlet conduits to the tubular end portions at the other ends of said track sections, means supplying a cooling liquid to said tubular track sections and to said induction coil including a manifold extending longitudinally and being supported by said parallel supports, coolant connections connecting said manifold and said induction coil, and means connecting said inlet conduits and said manifold.

3. An induction heating unit comprising a pair of longitudinally spaced substantially parallel supports having center openings in longitudinal alignment, a one-piece refractory tube supported by said parallel supports, a hollow induction coil encircling said tube, said induction coil including a plurality of coil turns, longitudinally extending supporting members circumferentially spaced about said tube for engaging and supporting said induction coil and tube, means connecting the end portions of said supporting members to said spaced supports, a track extending longitudinally within said tube, said track including a pair of laterally spaced tubular track sections supported on the interior surface of the tube and projecting therefrom to present a continuous projecting track section for supporting an article to be heated, laterally extending tubular end poriicns -On each @mi or each tratt Secties, meest for removably connecting each track section to said refractory tube comprising inlet conduits supported by one of the parallel supports, inlet fittings connecting the inlet conduits i9 the, iuiiii` lar end portions at one end of the track sections, outlet conduits supported by the other parallel support, outlety fittings connecting the outlet conduits to the tubular end portions at the other ends of said track sections, means supplying a cooling liquid to said tubular track sections and to said induction coil including a manifold ektending longitudinally and being Supported by said parallel supports, coolant connections connecting said manifold and said inductionV coil, and meansV connecting said inlet conduits and said manifold.

4. An induction heating unitcomprising a pair of longitudinally spaced substantially parallel supports having center openings in longitudinal alignment, a one-piece refractory tube supported by said parallel supports, a hollow induction coil encircling said tube, said induction coil including a plurality of interconnected coil turns, longir tudinally extending suppDr-ting members circumferentially spaced about said tube for engaging said coil and supportingv said tube along its length, means connecting the end portions of said sup.- porting members to said spaced supports, a track extending longitudinally within said tube, said track including a pair of laterally spaced tubular track sections supportedr on the interior surface of the tube and projecting therefrom tov pre.- sent a continuous projecting track section for supporting an article to be heated, laterallyv extending tubular end portions on, each endA ofeach track section, means for removably connecting each track section to said refractory tube. comprising inlet conduits supportedy by oneof the parallel supports, inlet fittings; connecting the. inlet conduits to the tubular end portions. at one end of the track sections, outlet conduits supported by the other parallel support, outlet fittings connecing the outlet conduits to the tubular end'portions at the other ends of said rack sections, meanssupplying a cooling liquid` to said tubular track sections including a manifold extending longitudinally andA being supported by said parallel supports, and means connectingv said? inlet conduits andsaid manifold.

5. An induction heating unit comprising a pair of longitudinally spaced parallel supports, a onepiece refractory tube supported on said supports.

tube, said track including a pair of laterally spaced tubular track sections supported on the inner cylindrical surface of said tube and projecting therefrom to provide a continuous projecting track section for supporting an article to be heated, tubular end portions on each end of each track section, means for removably connecting said track sections with respect to said refractory tube comprising inlet and outlet conduits, inlet fittings connecting the inlet conduits to the end portions of the track sections at one end, and outlet ttings connecting the outlet conduits to the end portions of the track sections at the other ends of said track sections, and means for supplying a coolant liquid to said track sections through said inlet conduits, said means including a manifold disposed longitudinally between said supports, and conduit means connecting said inlet conduits to said manifold.

6. An induction heating unit comprising a pair of longitudinally spaced parallel supports, a onepiece refractory tube supported on said supports, a hollow induction coil encircling said refractory tube, a track extending longitudinally within said tube, said track including a pair of laterally spaced tubular track sections supported on the inner cylindrical surface of said tube and projecting therefrom to provide a continuous track section disposed from the inner peripheral surface of the tube in spaced relation for supporting an article to be heated, tubular end portions on each end of each track section, means for removably connecting said track sections with respect to said refractory tube comprising inlet and outlet conduits, inlet ttings connecting the inlet conduits to the end portions of the track sections at one end, and outlet fittings connecting the outlet conduits to the end portions of the track sections at the other ends of said track sections, and means for supplying a coolant liquid to said track sections.

7. An induction heating unit comprising a pair of longitudinally spaced, substantially parallel supports having center openings in longitudinal alignment, a one-piece refractory tube supported within the opening, a hollow induction coil spirally wrapped around said tube and supported thereby, a track extending longitudinally within said tube, said track comprising a pair of laterally spaced tubular track sections supported on the inner surface of the tube and projecting therefrom, each tube presenting a continuous track surface disposed in spaced relation from the inner peripheral surface of the tube, for supporting an object to be heated, tubular end portions on said track sections extending laterally with respect to the sections and the refractory tube, means for supplying and discharging cooling liquid to and from said track sections including a manifold extending longitudinally substantially parallel with said refractory tube, an inlet conduit for each track section, an outlet conduit for each track section, the inlet'conduits being connected to said manifold for communication therewith and extending through said spaced supports, and first removable conduit connections connecting said inlet conduits with the tubular end portions at one end of said track sections, and second removable conduit connections connected to the tubular end portions at the other end of said track sections.

8. An induction heating unit comprising a pair of longitudinally spaced parallel supports, an integral refractory tube supported on said supports, a hollow induction coil encircling said reiractory tube, a pair of laterally spaced tubular track sections supported on the inner cylindrical surface of said tube and projecting therefrom to provide a continuous track section disposed throughout its length in spaced relation from the inner peripheral surface of said tube, for supporting an article to be heated, tubular end portions on each end of each track section, means for removably connecting said track sections with respect to said refractory tube comprising inlet and outlet conduits, inlet fittings connecting the inlet conduits to the end portions of the track sections at one end, and outlet fittings connecting the outlet conduits to the end portions of the track sections at the other ends of said track sections, and means for supplying a coolant liquid to said track sections.

9. An induction heating unit comprising a pair of longitudinally spaced supports, a one-piece refractory tube supported on said supports, a hollow induction coil encircling said refractory tube, a track extending longitudinally within said tube, said track including a pair of laterally spaced tubular track sections supported on the inner cylindrical surface of said tube and projecting therefrom to provide a continuous track section disposed. from the inner peripheral surface of the tube in spaced relation for supporting an article to be heated, means for removably connecting said track sections with respect to said refractory tube, and inlet and outlet connections on said tubular track sections for supplying coolant liquid to said tracks sections and for discharging the same therefrom.

NORMAN J. CUTLIFF. EMMETT V. BROGAN.

References Cited in the le of this patent UNITED STATES PATENTS 

